docs: add systemjs guide

README.md

@@ -32,6 +32,8 @@ testing your React components, you can consider using [jasmine-enzyme](https://g
 
 [Using Enzyme with Browserify](/docs/guides/browserify.md)
 
+[Using Enzyme with SystemJS](/docs/guides/systemjs.md)
+
 [Using Enzyme with WebPack](/docs/guides/webpack.md)
 
 [Using Enzyme with JSDOM](/docs/guides/jsdom.md)

docs/guides/systemjs.md

@@ -0,0 +1,73 @@
+# Using Enzyme with SystemJS
+
+If you are using a test runner that runs code in a browser-based environment,
+you may be using [SystemJS]() in order to bundle your React code.
+
+SystemJS uses static analysis to create a dependency graph at build-time of
+your source code to build a bundle. Enzyme has a hand full of conditional
+`require()` calls in it in order to remain compatible with React 0.13 and
+React 0.14.
+
+Unfortunately, these conditional requires mean there is a bit of extra setup
+with bundlers like SystemJS.
+
+In your SystemJS configuration, you simply need to make sure that the
+following files are labeled as "external", which means they will be ignored:
+
+```
+react/addons
+react/lib/ReactContext
+react/lib/ExecutionEnvironment
+```
+
+Here is an example piece of configuration code marking these as external:
+
+```json
+/* package.json */
+{
+  "jspm": {
+    "overrides": {
+      "npm:enzyme@2.3.0": {
+        "map": {
+          "react/addons": "@empty",
+          "react/lib/ExecutionEnvironment": "@empty",
+          "react/lib/ReactContext": "@empty"
+        }
+      }
+    }
+  }
+}
+```
+
+
+## React 0.14 Compatibility
+
+If you are using React 0.14, the instructions above will be the same but with a different list of
+externals:
+
+```
+react-dom
+react-dom/server
+react-addons-test-utils
+```
+
+## React 15 Compatability
+
+If you are using React 15, your config should include these externals:
+
+```json
+/* package.json */
+{
+  "jspm": {
+    "overrides": {
+      "npm:enzyme@2.3.0": {
+        "map": {
+          "react/addons": "@empty",
+          "react/lib/ExecutionEnvironment": "@empty",
+          "react/lib/ReactContext": "@empty"
+        }
+      }
+    }
+  }
+}
+```